Why the first five years are critical for babies’ brains

The first years of life are a period of extraordinary brain growth for babies, shaping how they learn, communicate and relate to the world around them. Research from the Institute for the Science of Early Years and Youth (ISEY) highlights just how critical these early experiences are in laying the foundations for lifelong development.

The research is led by Sam Wass, Professor of Developmental Psychology and Director of ISEY, who has spent years studying how babies’ brains develop in response to their early environments and relationships.

The brain’s raw learning capacity in the first five years far outstrips anything we see in adulthood,

said Professor Wass.

His research shows that between birth and age five, babies’ brains rapidly form and refine their most critical neural connections, long before formal schooling begins. During this time, babies learn some of the most complex skills of all, including language, movement, attention and emotional understanding.

Rather than benefiting from constant stimulation, Professor Wass’s work demonstrates that babies learn best through slow, simple and repetitious face-to-face interaction with familiar adults. These everyday moments of connection help babies make sense of their surroundings and build strong foundations for later learning. The research also highlights how the fast pace of modern life can make early development more challenging for babies, particularly when stress, distraction or time pressure reduce opportunities for calm, responsive interaction.